Mars: Olympus Mons, wide angle view

Olympus Mons, Mars’s tallest volcano, imaged by the Mars Global Surveyor spacecraft on April 25, 1998. North is to the left. Water-ice clouds are visible to the east (top) against the bordering escarpment and above the plains beyond. The central caldera, about 85 km (53 miles) across, comprises several overlapping collapse craters.